In recent years, in LTE (Long Term Evolution), carrying out channel definition in the physical layer according to scheduling differences is studied. As specific examples of this channel definition, there are channels such as the localized channel and the distributed channel based on the OFDM system.
FIG. 1 is a conceptual diagram of the localized channel and the distributed channel in the frequency domain. In FIG. 1, blocks 1, 2 and 3 show the distributed channel and blocks 4, 5, 6, . . . , 29 and 30 show the localized channel. Further, in this figure, three subcarriers are assigned to one block of the localized channel. Hereinafter, this block will be referred to as “RRB (Radio Resource Block).”
The localized channel refers to a method of assigning RRB's to users in the frequency domain and the time domain in a concentrated manner, and is directed to improving throughput by scheduling by assigning only RRB's of good received quality to users. Further, the operation of UE's includes measuring received power per RRB (in FIG. 1, blocks 4, 5, 6, 29, and 30) which is arranged in the localized channel, and calculating and reporting the CQI of each RRB, and Node B reports the scheduling result to UE's using RRB numbers.
On the other hand, the distributed channel refers to assigning RRB's in the frequency domain and the time domain in a distributed manner, and is directed to providing stable quality to users by obtaining frequency and time diversity. Further, the operation of UE's include calculating and reporting the CQI based on average full band received power, and Node B reports the scheduling result to UE's using RRB numbers.
In this way, first, UE's report the CQI's in RRB units (in the case of the localized channel) and are assigned schedulings in RRB units, and so need to learn how RRB's are arranged, that is, learn RRB arrangement information.
Next, the characteristics of the localized channel and the distributed channel will be described. The localized channel assigns high quality frequency band and time to users, and so high speed communication can be anticipated. Further, the localized channel needs to report the CQI's per RRB frequently, and, for this reason, cannot be applied to UE's which receive significant fading variation. In view of these, the localized channel is suitable for massive downloading services such as web browsing and is preferably used for users who are not moving at a high speed.
On the other hand, with the distributed channel, high speed communication cannot be anticipated but frequency diversity and time diversity can be obtained, so that stable communication can be anticipated. Further, the frequency of CQI report can be reduced compared to the localized channel. For this reason, the distributed channel does not carry out high speed transmission, but is suitable for services such as speech requiring stable quality, and so is preferably used for users when scheduling functions do not work effectively because users move fast.
In this way, uses are different between channels. For this reason, if the arrangement of the localized channel and the distributed channel is fixed, the distributed channel is likely to be assigned to users originally suitable for the localized channel, or, on the other hand, the localized channel is likely to be assigned to users originally suitable for the distributed channel. Therefore, the arrangement of the localized channel and the distributed channel is preferably variable.
The arrangement pattern of the localized channel and the distributed channel may be changed, for example, in the case where, for UE's in the same cell, the distributed channel is assigned to 20% of the UE's and the localized channel is assigned to the rest of 80% of the UE's (which is shown in the upper part of FIG. 2), and, in the case where the distributed channel is assigned to 10% of the UE's and the localized channel is assigned to the rest of 90% of the UE's (which is shown in the lower part of FIG. 2).    Non-Patent Document 1: “Downlink Channelization and Multiplexing for EUTRA,” Samsung, 3GPP TSG RAN WG1 Ad Hoc on LTE, R1-050604, Sophia Antipolis, France, Jun. 20 to 21, 2005.    Non-Patent Document 2: “Radio Resource Control (RRC) Protocol Specification,” 3GPP TR25.331